1. Field of the Invention
The present invention relates to a connector apparatus used for a flexible cable, and more particularly to a connecting apparatus used for the electric wire harness disposed between a steering wheel and a steering column of an automotive vehicle.
2.1. Prior Art
A conventional cable connector apparatus used for connecting the steering wheel and the steering column, disclosed for example in the Unexamined Japanese Patent Application No. HEI 4-19980/1992 and the Unexamined Japanese Patent Application No. HEI 5-39044/1993, has a small-diameter stationary member fixed to the steering column and a large-diameter rotary member fixed to the steering wheel. A flat cable is connected to the small-diameter stationary member at one end thereof and is connected to the large-diameter rotary member at the other end thereof.
In this kind of cable connector apparatus, an inside space of the casing is usually large enough to allow the flat cable to expand due to flexibility when this flat cable is unwound. However, the flat cable dose not always expand coaxially with an axis of the stationary member. That is, the flat cable tends to cause eccentric expansion around the stationary member in the unwound condition. If the radially outermost periphery end of the flat cable offsets too much toward one particular direction due to this eccentric expansion, the flat cable possibly causes frictional engagement or interference with the inside wall of the casing. This frictional engagement or interference is of course undesirable in properly winding the flat cable around the stationary member. Consequently, the flat cable is likely to cause unwanted permanent buckling.
2.2. Previously Proposed Art:
To solve above problem, the applicant of this application has already proposed a connector apparatus used for a steering apparatus in an automotive vehicle, recently applied for a patent to the Japanese Patent Office and is numbered as Japanese Patent Application No. HEI 5-53100/1993 which is not yet opened to the public. As shown in FIG. 10, this steering connector apparatus comprises a rotary member 35, a stationary member 36, a flat cable 37 having one end connected to the movable member 35 and the other end connected to the stationary member 36, and a casing 38 accommodating these members 35, 36, and 37 therein. The flat cable 37 is wound around both the movable member 35 and the stationary member 36 plural times.
To solve the problem encountered in the above-described conventional cable connector apparatus, the cable connector apparatus proposed by the applicant of the present application disposes the stationary member 36 at a position offset from the center 39 of the inside space of the casing 38 close to the cable passage, so that the offset direction becomes normal to the pulling-out direction of the flat cable.
However, longstanding usage of the flat cable in such a cable connector apparatus will inevitably cause permanent winding deformation of the flat cable. Therefore, the expanding direction of the flat cable 37 when unwound around the stationary member 36 and the rotary member 37 will be unexpectedly varied from the initial condition.
If the expanding direction of the flat cable 37 once varies largely due to aging effect, the flat cable 37 will be unable to avoid interference with the inside wall of the casing 38. And, therefore, the flat cable 37 will be fatally buckled. Thus, the above-described eccentric arrangement of the stationary shaft will be no longer effective against the longstanding usage of the flat cable.